.main {
    overflow: hidden;
    bottom: 132px;
    width: 100%;
    height: 750px;
    background: url(../upload/home_wrap20181203.jpg);
    .logo_mxd {
        margin-right: 100px;
        margin-top: 50px;
    }
    .nav {
        position: relative;
        width: 704px;
        height: 385px;
        background: url(../img/index_main.png);
        margin: 200px auto;
    }
    .nav>a {
        display: inline-block;
        width: 132px;
        height: 40px;
        margin-top: 24px;
        margin-left: 22px;

    }
    .link {
        position: absolute;
        bottom: 0;
        width: 700px;
        height: 300px;
        background: url(../upload/14943128782426.png);
        
    }   
    #link_main {
        width: 100%;
        height: 100%;
        display: block;
    }
    .circle {
        background: url(../img/download_bg.png) no-repeat;
        position: absolute;
        left: 50%;
        margin-left: 110px;
        top: -60px;
        width: 100%;
        height: 100%;
        
        .mxd_download {
            display: block;
            background: url(../img/home_btn.png) no-repeat 0px 0px;
            width: 200px;
            height: 200px;
        }
    }
}

